Bogner Amplification Uberschall Head with 6L6sUberschall is the German word for Super Sonic and we designed this amp primarily for extreme, heavy and aggressive styles of music. Detuned or baritone guitars crave this amp. Two versions are available, the UBERSCHALL with it's traditional clean and super high gain channels and the TWIN JET with a semi clean to hot rod gain and super high gain channel configuration. While the super high gain channels are identical there is more flexibility and